Is 113 IQ good for a 29 year old man?

100 is considered average. An IQ between 125-145 is optimal for social and educational development. 135 is generally the cutoff for being considered "gifted" in school. An IQ of 160 qualifies you as a genius, but social development among this group (the top .1% of US citizens, I believe - 3 standard deviations from the norm) is generally hindered.

The following is from giftedkids.about.com (each category, with an exception to the highest one, represents 1 additional positive standard deviation from the norm):

• Mildly Gifted -- 115 to 129
• Moderately Gifted -- 130 to 144
• Highly Gifted -- 145 to 159
• Exceptionally Gifted -- 160 to 179
• Profoundly Gifted -- 180

IQ scores are normalized by age, thus theoretically if you got an IQ score of 115 you should always get an IQ score of 115 throughout your life whenever tested. In actual practice deviations in score of about ±5 points are not considered statistically significant. However remember that the only thing an IQ score has ever been shown to consistently predict both reliably and accurately is the ability to score high on IQ tests.